The present invention relates to an adapter system for component assembly circuit boards, such as are employed in great number and in the most various designs in electronic apparatuses of the most varied size. Such circuit boards have individual electronic components mounted on them.
On such an component assembly circuit board there are a plurality of components, component assemblies and the like, and numerous contact and solder points are present, for which the possibility cannot be excluded that a component, a solder point or the like could be defective. As a result of such a defect, the complete component assembly board is for the most part not useable and would not be tolerable if built into an electronic apparatus, or would lead to complaints from the customer. It is thus provided to test the component assembly circuit boards for complete freedom from faults, each individually, in accordance with a test program to be determined. Thereby, inter alia, the large number of contact points are to be tested with a view to determining whether the conductor paths, components and assemblies present on the board between them have the required electronic properties. Clearly, this can be economically effected only by means of an automatically functioning test device, which tests at predetermined test points of the board the conductor path connections and the elements with which this component assembly circuit board is mounted. For such a testing which runs automatically, checking/test devices have been developed and are available which e.g. have in one plane a large number of contacts, e.g. spring contact tips. These contact tips are the respective external terminals of the test channels of the checking/test device, whereby the functions of the individual test channels are set in accordance with a standard. When the test points of a component or of a component assembly are connected each with such a contact tip, i.e. with a test channel of the test device, the connected element of the component assembly circuit board can be checked with regard to its freedom from faults with the test device.
There are known, e.g. from DE-A-4,226,069, standardized test devices with in each case a specific adapter part with which selected electrical connections between respective test points of an component assembly circuit board and respective contact tips of the test device are established. For this purpose, the plane of these contact tips and the component assembly circuit board are arranged parallel to one another and one above another with a spacing, and contact elements are located in the space between the board and the test device which contact elements establish these connections in a selected manner for the case concerned. For this purpose it is usual to provide respective pairs of contact pins connected with one another by an electrical wire, of which the one pin contacts the selected test point and the other pin contacts the respective associated selected contact tip of the test device.
With such known arrangements it is disadvantageous that individual, in some cases long, wire connections between the pins of a respective pair are to be provided, which give rise to high production costs and which may have undesirable effects in relation to high frequencies. Also, the manipulation therewith and the placement of the contact pin pairs is inconvenient and time consuming. Further, with this technique, problems can appear particularly in the case of circuit boards having higher packing density, because the available space is not always sufficient for the two pins respectively required per contact connection.
From EP-0233992 A1 there has been known for almost a decade a further test device having an adapter for contacting matching to a respective component assembly circuit board, and this device is in use. The adapter has first spring contact pins, fastened in a first plate, which pins correspond to the required contacting of test points of the circuit board, are directed towards the board and are positioned distributed over the plate with regard to the area thereof. Second contact pins of constant length are fastened in this plate, directed towards the test device, which second contact pins are each positioned associated with a respective one of the first spring contact pins, neighbouring that first spring contact pin. These respective pairs of contact pins are electrically connected with one another by wires. This known adapter also includes a second plate with the funnel-like holes of which, directed towards the second contact pins, the bendable contact ends of the second contact pins are so directed, upon pushing of the plate onto the ends of these contact pins, that the contacting ends meet the selected spring contact tips of the test device. With this known adapter there are always provided two pins of a pin pair for a respective connection between the contact tip of the test device and the test point of the board. For a respective connection there is thus needed space for two pins alongside one another. In the region of the connection of a large component module on the circuit board this requirement is not always satisfied.
From DE-A-3,248,694 there is known a further adapter system having a conductor path plate which is arranged between the test pin tips of the test device, which are positioned in a standard manner, and the likewise usual spring contact pins, with which the individual test points of the circuit board are contacted. The conductor paths of this plate are provided individually adapted to the circuit board concerned so that with these conductor paths, that is just as with the wires of the above-mentioned known designs, the respective lateral offsets of associated test contact tips and test points on the board is bridged. With the adapter system of this publication also, for each new circuit board a new conductor path plate with the specifically matched conductor pattern has to manufactured, and this plate also is usable as adapter only for this board.
From EP-0374434 A1 there is known still a further test device, however having a kind of universe adapter. There, in a first adapter plate for universal use, there are placed, one against another, axially displaceable contact pins of constant length. In an associated second adapter plate, individual pins for the specific use are mounted in selected positions, which pins can lift up the pins of the first adapter plate arranged in correspondence to this selection and thus bring only these pins into contact with respective test points of the board. The pins of the second plate are electrically connected with the terminals of the test device by respective moveable wire connections. The second plate provided with the pins is equipped in a manner individually adapted to the board to be tested.